scholarly journals Неполяризующие интерференционные системы, содержащие металлические слои

2019 ◽  
Vol 127 (9) ◽  
pp. 523
Author(s):  
Фам Ван Хоа ◽  
Нго Тхай Фи ◽  
Л.А. Губанова
Keyword(s):  
Spectral Range ◽  
Simple Structure ◽  
Spectral Characteristics ◽  
Reflection Coefficients ◽  
Small Discrepancy ◽  
Implementation Analysis ◽  
The Difference

The structure of nonpolarizing interference systems containing metallic layers is considered. The technique of searching metal-dielectric interference systems, providing a small discrepancy between the spectral characteristics reflection (transmission) for s- and p- polarizations, is presented. The constructions developed on the basis of the presented method have a rather simple structure that ensures the ease of their implementation. Analysis of the spectral characteristics showed that in the spectral range (460–580) nm, the difference between the integral reflection coefficients for s- and p- polarizations does not exceed 1%.

scholarly journals Search for designs of nonpolarizing interference systems

2019 ◽  
Vol 43 (4) ◽  
pp. 550-556 ◽  
Author(s):  
V.K. Pham ◽  
T.P. Ngo ◽  
L.A. Gubanova
Keyword(s):  
Layer Thickness ◽  
Transmission Coefficient ◽  
Spectral Range ◽  
Spectral Characteristics ◽  
Small Discrepancy ◽  
Quarter Wavelength ◽  
Film Forming ◽  
Integral Characteristics

This research looks into methods for searching of designs of nonpolarizing interference systems, which provide a small discrepancy between spectral characteristics of the energy reflection/transmission coefficient for s- and p- polarizations. The layer thickness of these systems is a multiple of a quarter wavelength. Depending on the method used, the number of film-forming materials can vary from two to four. Analysis of spectral characteristics shows that in the spectral range of interest the discrepancy between the integral characteristics for s- and p-polarizations is less than 2%.

scholarly journals Interpretation of Pseudocontinua in the Spectra of Highly Ionized Atoms from Tm To W in Laser Produced Plasmas

1984 ◽  
Vol 86 ◽  
pp. 215-218
Author(s):  
P. Mandelbaum ◽  
M. Klapisch ◽  
A. Krasnitz ◽  
A. Zigler
Keyword(s):  
Spectral Range ◽  
Simple Structure ◽  
Complex Pattern ◽  
X Ray ◽  
Long Wavelength ◽  
Line Identification ◽  
Laser Produced Plasma ◽  
Resonant Transitions ◽  
Wavelength Side

X-ray spectra of highly ionized atoms (Tm to Pt) emitted from Laser produced plasma are characterized by the simple structure given by resonant transitions of the Nil-like ions, accompanied by the more complex pattern of satellite transitions emitted by ions in the neighbouring states of ionization. An analysis of these structures has been given recently for the satellites of the 3d10 − 3d94p[l] and of the 3p63dl0 − 3p53d104s, 4d[2] transitions of the Nil-like inns. However, most of the radiation emitted in this spectral range [4–10Å] concentrate in a wide, rather structureless satellite feature in the long wavelength side of the 3d10 −3d94f Ni-I like transition, on which some lines are superimposed. Line identification has been achieved successfully with the methods of [1], [2] and will be published separately. In this communication, we deal only with the pseudocontinuum.

scholarly journals Quasi-biennial and quasi-triennial oscillations in the growth rates of atmospheric chlorofluorocarbons 11 and 12

MAUSAM ◽  
2022 ◽  
Vol 53 (3) ◽  
pp. 349-358
Author(s):  
R. P. KANE
Keyword(s):  
Southern Hemisphere ◽  
Growth Rates ◽  
Southern Oscillation ◽  
Spectral Characteristics ◽  
Linear Increase ◽  
Transport Processes ◽  
Emission Rates ◽  
Low Latitude ◽  
The Difference ◽  
Prominent Peak

The 12-monthly running means of CFC-11 and CFC-12 were examined for 1977-1992. As observed by earlier workers, during 1977-1988, there was a rapid, almost linear increase of these compounds, ~70% in the northern and ~77% in the southern hemisphere. From 1988 up to 1992, growth rates were slower, more so for CFC-11 in the northern hemisphere. Superposed on this pattern were QBO, QTO (Quasi-Biennial and Quasi-Triennial Oscillations). A spectral analysis of the various series indicated the following. The 50 hPa low latitude zonal wind had one prominent QBO peak at 2.58 years and much smaller peaks at 2.00 (QBO) and 5.1 years. The Southern oscillation index represented by (T-D), Tahiti minus Darwin atmospheric pressure, had a prominent peak at 4.1 years and a smaller peak at 2.31 years. CFC-11 had only one significant peak at 3.7 years in the southern hemisphere, roughly similar to the 4.1 year (T-D) peak. CFC-12 had prominent QBO (2.16-2.33 years) in both the hemispheres and a QTO (3.6 years) in the southern hemisphere. For individual locations, CFC-11 showed barely significant QBO in the range (1.95-3.07 years), while CFC 12 showed strong QBO in the range (1.86-2.38 years). The difference in the spectral characteristics of CFC-11 and CFC 12 time series is attributed to differences in their lifetimes (44 and 180 years), source emission rates and transport processes.

scholarly journals Design of Two Novel Dual Band-Notched UWB Antennas

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Bing Li ◽  
Jing-song Hong
Keyword(s):  
Time Domain ◽  
Simple Structure ◽  
The Other ◽  
Ultra Wideband ◽  
Dual Band ◽  
Uwb Antennas ◽  
Monopole Antennas ◽  
Printed Monopole ◽  
The Difference ◽  
The Time Domain

Two novel dual band-notched ultra-wideband (UWB) printed monopole antennas with simple structure and small size are presented. The size of both antennas is25×25×0.8 mm3. The bandwidth of one of the proposed antenna can be from 2.7 GHz to 36.8 GHz, except the bandwidth of 3.2–3.9 GHz for WiMAX applications and 5.14–5.94 GHz for WLAN applications. The bandwidth of the other is ranging for 2.7 to 41.1 GHz, except the bandwidth of 3.2–3.9 GHz for WiMAX applications and 4.8–5.9 GHz for WLAN applications. Bandwidths of the antennas are about 512% and 455% wider than those of conventional band-notched UWB antennas, respectively. In addition, the time-domain characteristics of the two antennas are investigated to show the difference between both antennas.

Charge Transfer Complexes of Aromatic Nitrocompounds with Disubstituted Naphthalenes. I.Spectroscopic Investigation of the Donor Behaviour of the 2,6- and 23-Dimethylnaphthalene

1984 ◽  
Vol 39 (12) ◽  
pp. 1274-1278 ◽  
Author(s):  
M. H. Abdel-Kader ◽  
R. M. Issa ◽  
M. M. Ayad ◽  
M. S. Abdel-Mottaleb
Keyword(s):  
Charge Transfer ◽  
Spectral Characteristics ◽  
Charge Transfer Complexes ◽  
Element Analysis ◽  
H Nmr ◽  
Aromatic Nitrocompounds ◽  
Donor Acceptor ◽  
The Difference ◽  
Donor Behaviour ◽  
Ct Complexes

The charge transfer complexes of 2,3- (I) and 2,6-Dimethylnaphthalenes (II) as electron donors with tri- and di-nitrobenzenes as electron acceptors are prepared and investigated by element analysis, IR. 1H nmr and electronic absorption spectroscopy. The results showed that I yields CT complexes of 1:1 type only while II is capable of forming 1 : 1 and 1 : 2 (donor: acceptor) compounds. The spectral characteristics of the CT complexes are pointed out and discussed. The difference in the donor behaviour between I and II is explained in the light of PPP-MO calculations.

Protonation and Acid-catalyzed Rearrangement of 1,2-Diazepines

1974 ◽  
Vol 52 (15) ◽  
pp. 2805-2817 ◽  
Author(s):  
David John Harris ◽  
M. T. Thomas ◽  
Victor Snieckus ◽  
E. Klingsberg
Keyword(s):  
Activation Energy ◽  
Trifluoroacetic Acid ◽  
Water Solution ◽  
Spectral Characteristics ◽  
Lone Pair ◽  
Pair Interaction ◽  
Protonated Form ◽  
Open Chain ◽  
Ring Inversion ◽  
The Difference

The protonation of the 1,2(4H)-diazepines 2a, 2b, and the 1,2(1H)-diazepine 3a in various acidic media has been studied by u.v. and n.m.r. spectroscopy. Compounds 2a and 3a undergo protonation to give 4a and 7a, respectively, whereas 2b provides the monoprotonated species 4b in dilute acid and the diprotonated form 4c in strongly acidic solution. Spectral characteristics of crystalline 1,2(4H)-diazepinium perchlorates 4a, 4d, 7a, and 7c correlate well with those observed for the corresponding free bases in acidic solutions; 7a-ClO4 and 7c-ClO4 were obtained either from 2a and 2c or from 3a and 3c, respectively. In trifluoroacetic acid-d-D2O, deuterium exchange at C4 and C6 of 2a, 2b, and 3a was observed indicating the presence of small equilibrium concentrations of species 1a, 1c and/or 1d, and 1b under these conditions. Temperature variable n.m.r. spectroscopy provides evidence for ring inversion phenomena for the protonated forms 4a and 7a. In the case of 4a, the activation energy, ΔGc≠ = 10.2 ± 0.2 kcal/mol (Tc = 8 ± 3°) has been estimated. The difference in the activation energy between the free base and the protonated form, ΔG≠ (2a)—ΔG≠ (4a) = 6–7 kcal/mol is attributed to strong repulsive N1—N2 lone pair interaction in 2a in the transition state for the ring inversion process.Under vigorous acidic conditions, the 1, 2(4H)-diazepines 2a–c give pyrazoles (10a–c), pyridines (12a–c), and acetophenone. Using identical conditions, the 1,2(4H)-diazepinium salt, 7a-ClO4 provides pyrazole 11a and pyridine 12a and, in addition, the 1-methylaminopyridinium salt 13a. However, rearrangement also proceeds under very mild conditions (ethanol–water) as shown for 7a-ClO4 and 7c-ClO4 which yield compounds 11a and 12a, and 11c, 12c, and 13c, respectively. The 1, 2(1H)-diazepine 3a gives 11a, 12a, and 13a in ethanol–water solution and exclusively 13a in trifluoroacetic acid. The mechanism of these reactions is discussed in terms of formation of open-chain (15) and diaziridine-type (19) intermediates. Electrocylic mechanisms are eliminated from consideration on the basis of the absence of products 23, 24, and 25 which should have been observed from the reactions of 2b, 2c, and 7c-ClO4 if these pathways were operative.

scholarly journals Assessing the Spectral Characteristics of Dye- and Pigment-Based Inkjet Prints by VNIR Hyperspectral Imaging

Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 603
Author(s):  
Lukáš Krauz ◽  
Petr Páta ◽  
Jan Kaiser
Keyword(s):  
Hyperspectral Imaging ◽  
Near Infrared ◽  
Hyperspectral Image ◽  
Spectral Characteristics ◽  
Principal Component ◽  
Hyperspectral Image Processing ◽  
Different Types ◽  
The Difference ◽  
Hyperspectral Camera

Fine art photography, paper documents, and other parts of printing that aim to keep value are searching for credible techniques and mediums suitable for long-term archiving purposes. In general, long-lasting pigment-based inks are used for archival print creation. However, they are very often replaced or forged by dye-based inks, with lower fade resistance and, therefore, lower archiving potential. Frequently, the difference between the dye- and pigment-based prints is hard to uncover. Finding a simple tool for countrified identification is, therefore, necessary. This paper assesses the spectral characteristics of dye- and pigment-based ink prints using visible near-infrared (VNIR) hyperspectral imaging. The main aim is to show the spectral differences between these ink prints using a hyperspectral camera and subsequent hyperspectral image processing. Two diverse printers were exploited for comparison, a hobby dye-based EPSON L1800 and a professional pigment-based EPSON SC-P9500. The identical prints created via these printers on three different types of photo paper were recaptured by the hyperspectral camera. The acquired pixel values were studied in terms of spectral characteristics and principal component analysis (PCA). In addition, the obtained spectral differences were quantified by the selected spectral metrics. The possible usage for print forgery detection via VNIR hyperspectral imaging is discussed in the results.

scholarly journals Evaluation And Selection Of Colour Spaces For Digital Systems

2020 ◽  
pp. 86-94
Author(s):  
Vera L. Zhbanova
Keyword(s):  
Spectral Characteristics ◽  
Colorimetric Method ◽  
Digital Systems ◽  
Colour Difference ◽  
Colour Space ◽  
Digital Devices ◽  
Initial Stage ◽  
Photo Detectors ◽  
The Difference ◽  
Selection Of

The research examined the changing of colour difference by the control colours depending on the choice of colour space when working with matrix photo detector. The spectral characteristics of photo detectors from different manufacturers noticeably differ from each other and from the addition the difference in colour quality between different digital devices. A software method for studying the colour rendition of the image obtained by digital devices based on the selection of an individual colour space for each matrix photo detector is proposed. To analyze and evaluate the capabilities of the spectral characteristics of matrix photo detectors, the control colour method based on the Mansell Atlas was used. The analysis of the obtained parameters of 14 colours was carried out according to various criteria for seven colour spaces: sRGB, AdobeRGB, DCI-P3 RGB, M1N1P1, PAL / SECAM, Wide Gamut RGB, ProPhoto RGB. Also studied the influence of the choice of colour space on the change in the coordinates of the source 6,500 K. Based on the colour differences of the control colours, it is possible to choose the optimal colour space for working with a specific matrix photo detector. The latter will reduce colour distortion at the initial stage of image registration. The ways for improving the colorimetric method of control colours are proposed as applied to digital devices at the software level.

scholarly journals Detection of Multi-pixel Low Contrast Object on a Real Sea Surface

2021 ◽  
Author(s):  
Victor Golikov ◽  
Oleg Samovarov ◽  
Daria Chernomorets ◽  
Marco Rodriguez-Blanco
Keyword(s):  
Spectral Characteristics ◽  
False Alarm Probability ◽  
Sea Surface ◽  
Statistical Characteristics ◽  
Statistical Parameters ◽  
Low Contrast ◽  
Video Images ◽  
Floating Object ◽  
The Difference ◽  
Floating Objects

The video images captured at long range usually have low contrast floating objects of interest on a sea surface. A comparative experimental study of the statistical characteristics of reflections from floating objects and from the agitated sea surface showed the difference in the correlation and spectral characteristics of these reflections. The functioning of the recently proposed modified matched subspace detector (MMSD) is based on the separation of the observed data spectrum on two subspaces: relatively low and relatively high frequencies. In the literature the MMSD performance has been evaluated in generally and moreover using only a sea model (additive Gaussian background clutter). This paper extends the performance evaluating methodology for low contrast object detection and moreover using only the real sea dataset. This methodology assumes an object of low contrast if the mean and variance of the object and the surrounding background are the same. The paper assumes that the energy spectrum of the object and the sea are different. The paper investigates a scenario in which an artificially created model of a floating object with specified statistical parameters is placed on the surface of a real sea image. The paper compares the efficiency of the classical Matched Subspace Detector (MSD) and MMSD for detecting low-contrast objects on the sea surface. The article analyzes the dependence of the detection probability at a fixed false alarm probability on the difference between the statistical means and variances of a floating object and the surrounding sea.

scholarly journals Surface and optical properties of calcium carbonate paper

2021 ◽  
Vol 57 (4) ◽  
pp. 472-479
Author(s):  
I. I. Ismailov ◽  
Kh. A. Babakhanova ◽  
A. A. Sadriddinov ◽  
M. A. Babahanova ◽  
D. Sh. Saidova
Keyword(s):  
Optical Properties ◽  
Calcium Carbonate ◽  
Quantitative Assessment ◽  
Incident Light ◽  
Reflection Coefficients ◽  
Paper Sample ◽  
Surface Reflection ◽  
Coated Papers ◽  
Paper Company ◽  
The Difference

The article investigates the surface and optical properties of calcium carbonate paper obtained at the UzbekChinese enterprise Fergana stone paper company (Uzbekistan), in order to identify the possibility of their use at printing enterprises for printing multicolor products using traditional printing methods. According to the results of a quantitative assessment of the surface quality by the indirect Beck method, we can say that paper sample 1 has a smoothness like coated paper (750–1500 s), paper samples 2 and 3 – like calendered paper, so that these paper samples can be recommended for prints with increased quality requirements. Smaller values of roughness Ra and small depressions, expressed by darkening in the topographic AFM images, characterized sufficient homogeneity and density of the structure. It was also revealed that the surface of the paper samples has a high ability to specularly reflect the incident light, since the percentage of surface reflection is similar to that of coated papers. Samples of paper have a whiteness of about 90 % and do not have a tint, since the difference between the maximum and minimum values of the reflection coefficients on a white stack is not more than 10 %. The tested paper samples can be recommended without restrictions for double-sided printing, since the opacity index is more than 92 %.

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